Comsol continuation parameter. Then enter some model parameters.

Comsol continuation parameter In contrast, the second study applies a mathematical optimization algorithm that uses L as the control variable and the deviation from the target frequency as the optimization objective for fast, precise, and 7 In the Settings window for Semiconductor, click to expand the Continuation Settings section. The other solver parametric sweep is done i. Enter a Reference temperature for energy levels T 0 (SI unit: K). We can set the length scale here right away. The unit becomes orange if the unit that you specify does not match the unit Note: This discussion is about an older version of the COMSOL Multiphysics (outer) parametric seep and the solver "continuation sweep". 05,1. Simulating Radiation Effects in Semiconductor Devices. For User defined enter a Continuation parameter C p (dimensionless) between 0 and 1 to determine the scaling of the equation contribution. Then, the dosage rate can be specified by the parameter RadSi directly in units of Rad(Si)/s. • This variable gives the continuation parameter step size for parametric continuation solver simulations. Set the time parameter t to the pulse duration tp, then use the parameter RadSi to specify the dosage rate. • Does anyone know how to get the desired graphs axis from the table when using a continuation parameter and auxiliary sweep, study 1 and 2 respectively? Initially the probe plots (9total) is a 3 spikes (acceleration vs. If I fix the problem and I do not want to reprocess those parameter values which succeeded, how can I run the simulation for only the remaining parameters, and accumulate the results so that finally I have the complete set of solutions? I am new to COMSOL. Scale 1 (sca1) 1 (Time continuation parameter) range(0,0. E. The model represents a 2D MOSFET where the n-doped drain and source contacts continuation parameter is used to ramp up the electron and hole perpendicular components of the field (E. So in the nutshell how can I run multiple parameter sweeps while keeping the previous results from a previous sweep. -A parametric sweep is added with "freq" as the parameter and the wanted frequencies as parameter values. In this example, either method can be used. Using this black-box approach, they can efficiently gain the information needed for COMSOL Multiphysics has two ways to perform parametric studies — using either a Parametric Sweep node or the Auxiliary sweep from the Stationary Solver node. 3 introduces an interface for computing RLGC parameters for multiconductor transmission lines. Selecting User defined allows the parameter to be specified within the feature or select Use interface level continuation parameter to specify the parameter on the physics interface level. the solver "continuation parameter sweep" typically for steady state solvers, but also in some sens for frequency domain and I am not sure if the extension drop down really helps since there is no a continuation option. You can also click the downward arrow beside the Browse button and choose Browse From to open the fullscreen Select File window. We then introduce the Optimal Cooling of a Tubular Reactor tutorial model, which will serve as our new guided tutorial example. For this tutorial, it is appropriate to ramp up Δ T from 10 -3 K to 10 K, which corresponds to The Semiconductor physics interface provides a convenient mechanism to ramp up several quantities simultaneously by using a common continuation parameter as a multiplication factor. To enable the continuation solver, a parameter should be set in the Continuation parameter section and ramped from 0 to 1, which determines the But the continuation can use combination of parameters, correct? Would that work if i defined 5 global variables, for instance? And how would I define the max and min values? I am bit confused on that part. let’s introduce a Global Parameter called dLength to represent the difference in length. comsol continuation parameter, COMSOL Multiphysics Server This application launches the Terminal application and starts a COMSOL Multiphysics Server in a Use the table with Parameter name, Parameter value list, and (optional) Parameter unit to specify parameter names, values, and units for the parametric solver. Best Regards, Rui where \rho denotes the density and \mu is the dynamic viscosity of the fluid. For sweeptype=filled, all parameter combinations given by plistarr are solved for. This includes least-squares optimization methods, which can estimate one or more of the input parameters. Within this framework, it is shown that a concurrent bifurcation analysis may be carried out together with parameter continuation of the corresponding monodromy matrices. Is there a way to access the parameter value during solution for tuning? I defined a A computational framework is proposed to perform parameter continuation of periodic solutions of nonlinear, distributed-parameter systems represented by partial differential equations with time The restriction \({\mathbf {E}}\big |_{\mathbb {I}}\) obtained by fixing a subset \({\mathbb {I}}\) of continuation parameters is equivalent to a reduced continuation problem To use a "continuation" stationary solver input, you must first define a Global Definitions Parameter with the name you want. This allows models to be solved with small contributions from these models initially, with a gradual Note that while COMSOL employees may participate in the discussion forum, COMSOL ® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team. A global parameter is introduced (pictured in the figure above, parameter P) to the model by being defined under the Global Definitions node in the Parameters table There is also an option to run a Stationary study with an Auxiliary sweep, with or without a continuation parameter. Is there a way to access the parameter value during solution for tuning? I defined a "flag" in the parameter list and use it as continuation parameter. To introduce the doping from a specific feature independently of the other features, select User defined and manually enter the Continuation parameter. I ramp the initial stress as The thermal load for these two geometries is applied in a sequence, first geometry has thermal load and then second geometry has thermal load. Do not forget to select the mobility model in the Semiconductor Material Model node, otherwise the mobility model subnode has no effect. 3b 2 | POSTBUCKLING ANALYSIS OF A HINGED CYLINDRICAL SHELL ©2013 COMSOL Figure . Click the downward arrow for the Location menu to choose Show in Auxiliary Data to move to the row From the Doping and trap density continuation parameter list, choose Use interface continuation parameter. 1 shows the variation of load versus the displacement for such a difficult case. To use continuation you need to both select the Auxiliary Sweep check box as well as select one of the parameters as the continuation parameter from the list under Study Extensions on the Stationary or Frequency Domain node’s Settings window. Solved with COMSOL Multiphysics 4. Of course, it is always instructive to go into the solver settings to see what settings the software has chosen. The optimization without milling constraints results in a closed spherical design with an internal cavity. Click the Create button in the section header to set up the nonlinear study. Perhaps this is why the solver does not converge (ie because you are using a different initial guess than if you simply solve for the single parameter). 1 there is an updating issue of the TWO occurences of the parameter sweep and continuation/extension fields, you must update BOTH sub nodes 7 In the Settings window for Semiconductor, click to expand the Continuation Settings section. 0 or higher), in particular, the option "Continuation" in the "Extension" submenu of a stationary study does it mean that it performs an Arc-Length path-following? which also loops around the geometry and the mesh, hence if you have a parameter that changes the geometry it will . A parametric sweep allows you to change the parameter values through a specified range. 4 2 | LOMBARDI SURFACE MOBILITY. 2 In the Settings window for Parameters, locate the Parameters section. This design is impossible to manufacture with conventional subtractive manufacturing methods, which makes the problem Hi in 3. ⊥, n. • The parametric solver supports two algorithms, continuation and no continuation (plain sweep). In this example, both methods are applicable and the continuation feature in the Solver node is used. by Chien Liu. COMSOL Multiphysics has two ways to perform parametric studies—using either a Parametric Sweep node or the continuation feature from the Stationary Solver node. The "Continuation" method uses the solution of the previous parameter as the initial guess at the solution of the next parameter and so on. Note that while COMSOL employees may participate in the discussion forum, The COMSOL Multiphysics The value of the objective and the continuation parameters are shown for every iteration. A global parameter is introduced (pictured in the figure above, parameter P) to the model by being defined under the Global Definitions node in the Parameters table The Model Wizard exits and starts the COMSOL Desktop at the Geometry node. The default is to use the initial The parametric solver supports two algorithms, continuation and no continuation (plain sweep). 5) COMSOL MULTIPHYSICS provides embedded discretization algorithms capable of accommodating a great variety of mechanical/physical assumptions and MULTIPHYSICS interactions. Acoustics using COMSOL for modelling loudspeakers and room acoustics. It changes an input mobility to account for surface effects, particularly surface roughness and scattering due to acoustic phonons. Within the Settings window for the Parametric node, selecting the Constant option for the Predictor setting By tuning the continuation parameter the solver should use a step of flag/10 during solution process. Parameters. Particular functionality may The length unit in the imported geometry is centimeters, while the default length unit in COMSOL Multiphysics is meters. (load) and clamped perimeter of the square. Best Regards, Rui This can improve the convergence of the problem significantly. Parameters can have units. There is also an option to run a Stationary study with an Auxiliary sweep, with or without a continuation parameter. For User defined enter a value for the Doping and trap density continuation parameter C p (dimensionless). Implementing the Previous Solution Operator in COMSOL Multiphysics I checked auxiliary sweep in my stationary solution and added the parameter (which i before defined in global definitions as 1[1]. number of values computed consecutively for each corresponding user-defined internal pressures). 1. In order to design a battery system for a device, engineers can use lumped models, which may give reliable predictions within a given range of operation by performing parameter estimations via the COMSOL Multiphysics® software and add-on Optimization Module. The guidance provided here is specific to cases where the iterative solver is used. sweeptype=filled, all parameter combinations given by plistarr are solved for. Using the Model Builder, we can select the 0D Reaction Engineering interface with a time-dependent study from the Model Wizard. For stationary models with an auxiliary sweep over a ramping parameter, the default behavior is to use the continuation method. This design is impossible to manufacture with conventional subtractive manufacturing methods, which makes the problem Continuation Settings section. Is your parameter some way affecting geometry or the mesh specifications? Cheers Edgar Then use the Study Extension Continuation Sweep and not an Explicit Parametric Sweep (the latter runs through the mesher), and you should perhaps turn of the default "automatic mesher" and convert it to a user mesh Note that while COMSOL This inverse type of modeling requires parameter estimation. Now in Study 1 --> Step 1 : Stationary-->Study extensions-->Continuation, the model proposes to add the parameter para in the 'Continuation parameter' column and the following : " range(0,0. 3 In the table, enter the following settings: Set the interface to use the continuation parameter. Note that a specific parametric sweep goes around the geomery (and restarts at initial conditions) while a continuation sweep is good for non geometrical variables ad takes into account the previous steps to extrapolate where to go for This model is licensed under the COMSOL Software License Agreement 6. The Optimization Module, an add-on to COMSOL Multiphysics ®, offers features for parameter estimation, which can be used for estimating stationary, time-dependent, and space-dependent input parameter values. To handle, the "Initial values of variables solved for" you can set the Selection to Automatic and then use the Study Extensions section to define the wavelength (lam0) as 2nd continuation parameter (besides the V_appl which you already have). The Add solution data points from the General non-continuation Parameter value lists checkbox is selected by default to control if extra data points should be added to the solution process. Move the lam0 parameter first in the list and then specify "Sweep type" as All Combinations. This inverse type of modeling requires parameter estimation. 15 K. Finally enter the parameter "ramp" in the parameter table. I tried it for your problem and was able to engage the contact. 01[m] 3) draw a rectangle let us say 1m in x, and "Th" in Y 4) add a Fixed constraints on boundary 1 5) add a Body load Fy = -g_const*solid. The default is 1. 2 each time. During solving a parameter might be updated by a Parametric sweep node, or a solver continuation sweep tab. Continuation can only be used for Try using the Continuation solver and ramping the prescribed displacement from 0 to -0. Dimitrios Grevenitis If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. The default domain feature is the Semiconductor Material Model, which adds these equations to the domain, solving for the Comsol multiphysics provides embedded discretization algorithms capable of accommodating a great variety of mechanical/physical assumptions and multiphysics interactions. The Optimization Module, an add-on to COMSOL Multiphysics ®, offers features for parameter estimation, which can be used for estimating stationary, time-dependent, and The first study uses a parametric sweep of the tuning fork’s arm length, set as a parameter L, to find the optimal design for 440 Hz. The Lombardi Surface Mobility Model (S) subnode is available from the context menu (right-click the Semiconductor Material Model parent node) or from the Physics toolbar, Attributes menu. From the Continuation type list, choose Use interface continuation parameter. Use the Stationary study step’s continuation option with Δ T as the continuation parameter to get a solver sequence that uses previous solutions to estimate the initial condition. and . The continuity settings allow the trap densities to be weighted by an external parameter whose value should be between 0 and 1. Continuation can only be used for one The Deformed Geometry interface of the CAD Import Module of COMSOL Multiphysics allows you to modify the geometry of imported CAD files. To monitor the stabilization energy added, add a Global Variable Probe of the variable < phys>. Click the Save to File button () and enter a File name in the Save to File dialog box, including the extension . When a continuation parameter is selected, the continuation algorithm is run, which assumes that the sought solution is continuous in these parameters. Use the function mphsolutioninfo to retrieve the solution vector corresponding to a specified study parameter value. Therefore, you need to rescale the geometry. 05, etc. Problem in solving multiple parameter value problem on MAC . All optimization solvers are accessible from the same Optimization study step, which For User defined an input for the Continuation parameter appears and this should be set to a parameter with values between 0 and 1 to determine the scaling of the equation contribution. Radiation effects in semiconductors is a broad and complex topic, affecting many technical areas such as the electronics industry, medical imaging, nuclear engineering, and aerospace and military applications. The setting for Reuse solution from For User defined enter a value for the Doping and trap density continuation parameter C p (dimensionless). The model is an example of a multiphysics optimization problem, of which the physics include heat transfer in fluids, species transport, From the Continuation type list, choose Use interface continuation parameter. If you still need help with COMSOL and have an on-subscription license, please visit The continuation method is enabled by default when using the Auxiliary sweep study extension, as shown below. 6 over a range of values. The default selection is all domains where the expression is defined. Now, to specify nonzero radiation, just set the time parameter t to the pulse duration tp, so that the pulse function pw1(t/tp) is unity. Although, the final parameter step was having some difficulty the contact still was engaging. This should be set to a dimensionless I am wondering if it is possible to use the Continuation feature in the solver to optimize a value. In the . I am new to COMSOL. Additionally, you can save the parameters to a text file to reuse in other models. node, then click Solved with COMSOL Multiphysics 4. Best regards, Magnus Ringh, COMSOL When a continuation parameter is selected, the continuation algorithm is run, which assumes that the sought solution is continuous in these parameters. The default is to use the initial I have a quick question about the new features in Comsol (4. • The other parametric sweep, is inside the stationary study under Extension Continuation. Semiconductor Material Model 1. To use continuation you need to select the Auxiliary Sweep check box as well as select one of the parameters as the continuation parameter from the list under Study Extensions on the Stationary or Frequency Domain node’s Settings window. November 20, 2019. 7 In the Settings window for Semiconductor, click to expand the Continuation Settings section. The Reynolds number is the ratio of the inertial forces to the viscous forces in the flow. e. EDT 0 Replies . DEFINITIONS Variables 1 The continuation solver in COMSOL will then automatically perform a search over the interval between the last successful load value and the next desired load step. Sometimes the simulation fails at one of these values, and the sweep stops. Your external Parametric Sweep node tells COMSOL to loop all around the model, (I believe not rereading Parameters, but all the rest Yes) in this way your parameter sweep can update the geometry, get the mesher to remesh, and then Solve the model. The default is 293. I tried two make two rows in study continuation or to choose "ALL" in parameters values in the folder "Variables not solved for" but any time only last value of inlet velocity is used. When choosing the Use interface continuation parameter This paper treats comprehensively the construction of problems from nonlinear dynamics and constrained optimization amenable to parameter continuation techniques and with particular emphasis on multi-segment boundary-value problems with delay. For this tutorial, it is appropriate to ramp up Δ T from 10 -3 K to 10 K, which corresponds to When continuation is enabled by setting Run continuation for to one of the parameters, the converged solutions are always reused for the steps along the continuation sweep in this parameter. Later on this can be used in an auxiliary sweep in a study step to ramp the impurity concentration up from a small value. If no continuation parameter is given, a plain sweep is performed where a The Semiconductor (semi) interface (), found under the Semiconductor branch when adding a physics interface, solves Poisson’s equation for the electric potential and the drift-diffusion equations for electrons and holes in a semiconductor material. However, with To introduce the doping from a specific feature independently of the other features, select User defined and manually enter the Continuation parameter. Solving. When continuation is enabled by setting Run continuation for to one of the parameters, the converged solutions are always reused for the steps along the continuation sweep in this parameter. My experience with remeshing is in contrast with what In Part 5 of this course on optimization, we begin by briefly summarizing the two model examples completed in Part 4. m. In this 18-minute archived webinar, you will get an introduction to using the Optimization Module for performing A parameter expression can contain: numbers, other parameters, mathematical constants, physical constants, user-defined functions, functions of parameter expressions, unary operators, and binary operators. The continuation solver uses the solution from the previous parameter By default the Continuation Settings for the doping features link to an interface-level doping continuation parameter that can be set up in the Continuation Settings section of the Semiconductor interface’s Settings window. ) I chose Specified combinations, gave a range of 4 steps and chose run continuation for last parameter (but it is the same for no parameter and then reuse solution yes) COMSOL behaves differently depending on how you define a parametric sweep. The COMSOL Multiphysics The value of the objective and the continuation parameters are shown for every iteration. The model is an example of a multiphysics optimization problem, of which the physics include heat transfer in fluids, species transport, I have two parameters (defined as global parameters) which are used in initial value and boundary value of the problem. Later on this can be used in To avoid this, add a "Parameter" t = 0[s], this will be overwritten by COMSOL once the time solver comes up Sometimes it is better to use a value slightly different from "0" to avoid all =0 in your variables, this is all model and case dependent ;) Note that while COMSOL employees may participate in the discussion forum, By tuning the continuation parameter the solver should use a step of flag/10 during solution process. This design is impossible to manufacture with conventional subtractive manufacturing methods, which makes the problem I checked auxiliary sweep in my stationary solution and added the parameter (which i before defined in global definitions as 1[1]. For instance, have a flow in a pipe and using some data like pressure drop, Boston Scientific Public –Public Release Authorized Procedure Step 0: Create UI in App Builder to specify time-dependent factors Step 1: Link data structures to UI For users of the RF Module, COMSOL Multiphysics ® version 6. The unit becomes orange if Comsol can’t solve the flow field for high-speed ( 10 m/s) and even decreasing the relative tolerance it approaches the desired speed (but does not reach it), but the computation takes a lot of time ( 5 days). These solution vectors can be available in different solution datasets. frequency domain, eigenvalue, or stationary with continuation parameters: data = mphint2(model, <expr >, edim,'solnum', <solnum>) where <solnum> is an integer In order to design a battery system for a device, engineers can use lumped models, which may give reliable predictions within a given range of operation by performing parameter estimations via the COMSOL Multiphysics® software and add-on Optimization Module. The setting for Reuse solution from previous step then determines how the solutions are reused between multiple continuation sweeps, if there are Comsol multiphysics provides embedded discretization algorithms capable of accommodating a great variety of mechanical/physical assumptions and multiphysics interactions. COMSOL Blog. If you are using the continuation feature the plot will be updated for each parameter value. 2, and if it can't converge very very easily it changes the parameter back to take smaller steps of 0. In particular, the Note that the continuation parameter cp is used to control the amount of field dependence for aiding the solution process. However, the simulation takes longer to converge as the number of remeshing steps increases by doing this. Click Save to store the parameters in a text file or in a Microsoft Excel Workbook spreadsheet if the license includes LiveLink™ for Excel ®. Continuation can only be used for The Deformed Geometry interface of the CAD Import Module of COMSOL Multiphysics allows you to modify the geometry of imported CAD files. txt. The parametric solver supports two algorithms, continuation and no continuation (plain sweep). We then use the same Newton method as before on a series of problems with the parameter \beta, getting ramped The Continuation Settings section in several semiconductor physics feature nodes. Then, the dosage rate can be specified by the parameter RadSi directly in units of I want COMSOL to change the parameter by 0. Continuation can only be used for one The Model Wizard exits and starts the COMSOL Desktop at the Geometry node. Dear all, Using auxiliary sweep in Comsol, what is the difference between this two cases : 1/ Run continuation for : "Last parameter" 2/ Run continuation for : "No parameter" + Reuse solution from previous step : "Yes" I tried both, and I got a much quicker convergence (3 times faster) in case 2. 2, and then solve the model, and then change the parameter by 0. The process is of continuation type for time stepping and when the parametric solver is changing its continuation parameter. Enabling "Results While Solving" in "Step1: Stationary" will update the specified plot after computation of the whole solver sequence. If no continuation parameter is given, a plain sweep is performed where a then leave the geometrical parameter loop in the "external parametric" sweep, and check the "extension - continuation" box on the stationary solver (new feature n V4) and add the physical variable parameter here, this will make an internal sweep for each external geometrical sweep--Good luck Ivar The geometry nodes accept only Parameters or equations assembled with parameters. A model can contain several solution vectors computed with different values of parameters, such as time, eigenvalue, or model parameters. When solving a multiphysics problem, COMSOL will assume coupling between all physics, and try to choose the optimal fully coupled or segregated approach, based on the physics and the problem size. See attached *. If no continuation parameter is given, a For stationary models with an auxiliary sweep over a ramping parameter, the default behavior is to use the continuation method. Here we will ramp up the doping and thermionic current. If the evaluation point does not belong to the specified domain selection, the output value is NaN. Model Definition. To enable the continuation solver, a parameter should be set in the Continuation parameter section and ramped from 0 to 1, which determines the scaling of the equation contribution and slowly increases the nonlinear contribution to the system. Further Learning. Later on this can be used in then leave the geometrical parameter loop in the "external parametric" sweep, and check the "extension - continuation" box on the stationary solver (new feature n V4) and add the physical variable parameter here, this will make an internal sweep for each external geometrical sweep--Good luck Ivar Now, to specify nonzero radiation, just set the time parameter t to the pulse duration tp, so that the pulse function pw1(t/tp) is unity. I have successfully run a stationary study with coupled laminar flow, nernst planck and electrostatics. As far as I have understood, the continuation solver can be used only with an Auxiliary Sweep. Hi run a parametric sweep (i. Once again;): in versions prior to 4. ) I chose Specified combinations, gave a range of 4 steps and chose run continuation for last parameter (but it is the same for no parameter and then reuse solution yes) The continuation method is enabled by default when using the Auxiliary sweep study extension, as shown below. This allows models to be solved with small contributions from these models initially, with a gradual model with respect to design parameters (model parameters) such as parameters which control the geometry sequence that defines the model’s geometry. From the Doping and trap density continuation parameter list, choose Use interface continuation parameter. It illustrates the possible computational problem by using either a load control (path A) or a displacement control (path B). <seltag> can also be a positive integer array that corresponds to the domain index list. Global Definitions. To display this section, click the Show button and select Advanced Physics Options. In other words, we divide our spring stiffness function into two parts — a linear term, k(u_0), and a nonlinear term, \left[ k(u) – k(u_0) \right] — and then introduce an additional parameter, \beta, that interpolates between the linear and nonlinear case. Let us take a look at how you can implement and use this Previous Solution operator in a transient model in COMSOL Multiphysics. U is a characteristic velocity and d is a characteristic length of the modeled system. The information is saved in space-separated Hi I was just following your idea there, while readingyour question. Semiconductor Material Model 1 1 In the Model Builder window, click Semiconductor Material Model 1. 3 From the Continuation type list, choose Use interface continuation parameter. 005, Notes About the COMSOL Implementation. Best Regards, Rui From the Doping and trap density continuation parameter list, choose Use interface continuation parameter. That is, when solving, the software starts with the use In order to run a parametric continuation, select the Auxiliary sweep check box under Study Extensions for the Stationary or Frequency Domain study step. With this, we specify the deformation of the domain at the far end of the wrench to be (dx,dy,dz) = (dLength,0,0 The continuation solver in COMSOL will then automatically perform a search over the interval between the last successful load value and the next desired load step. 0a and trying to run a simple model with a parametric sweep. Best Regards, Rui In Study 3, two study steps were utilized. That is, the solver tries to backtrack to find an intermediate solution that can then be used as a starting value for the next step. Parametes are static variables, loaded once at beginning of solver run. The timestep , CFLCMP , and CMPpcontstep variables are available for postprocessing. Model Builder. The setting for Reuse solution from previous step then determines how the solutions are reused between multiple continuation sweeps, if there are To introduce the doping from a specific feature independently of the other features, select User defined and manually enter the Continuation parameter. 0. Then on the study node’s When you add a Stationary or Frequency Domain study, a parametric continuation solver is used to find the solution to a sequence of stationary PDE problems that arise when you vary some In Study 3, two study steps were utilized. The Auxiliary sweep can be used to implement ramping of any parameter. GLOBAL DEFINITIONS. Instead, it changes the parameter by 0. I know that a sweep involving changes in the geometry requires a Parametric Sweep, but to improve the convergence of the simulation I would like to set a "continuation solver" for the displacement parameter. We then discuss the use cases for the Curve Fitting study step and Parameter Estimation study step and what types of problems each are best suited to solve. The unit becomes orange if the unit that you specify does not match the unit The combination of COMSOL ® products required to model your application depends on several factors and may include boundary conditions, material properties, physics interfaces, and part libraries. But these two have a different behaviour on the "restat conditions". By controlling this parameter, the warning disappears. The ‘S’ in brackets indicates that the model includes The Semiconductor physics interface provides a convenient mechanism to ramp up several quantities simultaneously by using a common continuation parameter as a multiplication factor. 2 In the Settings window for Semiconductor Material Model, locate the Mobility Model section. window, expand the . This option can be useful to control the activation based on a specific parameter value in a continuation sweep, or at a specific time in a time-dependent solver. ⊥, p Now, to specify nonzero radiation, just set the time parameter t to the pulse duration tp, so that the pulse function pw1(t/tp) is unity. In COMSOL Multiphysics, under the Application Libraries, there are several tutorial models we recommend for additional self-guided practice in performing parameter I know that a sweep involving changes in the geometry requires a Parametric Sweep, but to improve the convergence of the simulation I would like to set a "continuation solver" for the displacement parameter. I don't want the parameter to change by anything except 0. This loop does NOT pass over the geometry and mesh, so these remain, but the physics is swept with the defined parameter(s) and each new parameter step, starts with the initial conditions of the previous step. A global parameter is introduced (pictured in the The default solver settings for a turbulent flow simulation is a segregated solver sequence. By default the Continuation type is set to Use interface continuation parameter. Use the table with Parameter name, Parameter value list, and (optional) Parameter unit to specify parameter names, values, and units for the parametric solver. Continuation Settings section. 9 From the Doping and trap density continuation parameter list, choose Use interface continuation parameter. Defining a parameter called “Tiso” (for the system temperature This last option controls how a parametric sweep is included, either as an external loop running around the full model geoemtry, mesh physics study initialising to "0" default initial cases, and the "study continuation" (if possible) looping only the study and using each solver run to as initial conditions and starting point for the next run where <seltag> is the tag of a selection node to use for the data evaluation. Or an example in the comsol literature. If Study is set to New, a new study is created. stationary continuation sweep) with Param = range(0,0. Within the Settings window for the Parametric node, selecting the Constant option for the Predictor setting will make the convergence more robust but slower. Enter the continuation parameter, ramp, in the interface continuation parameter field. For example, a parameter can be defined as (exp(-pi*i)+a)*c_const, where a is another parameter, but it is often a scalar numerical value There is also an option to run a Stationary study with an Auxiliary sweep, with or without a continuation parameter. As of COMSOL Multiphysics® software version 5. I used stationary study step, checked the Auxiliary sweep, and add a parameter T in the parameter name, specified combinations, the range is set like range(100, 100, 200). Input Mobilities. Run continuation for "Last parameter": With this option, COMSOL will use the solution from the previous step as the initial guess for the current step, and will attempt to continue the solution In 4. 02,1) range(1. In addition, flexibility is provided so that custom or Add a continuation parameter to be used in the continuation study. Adding the name of a parameter to this setting and ramping it from 0 to 1 in the continuation solver will gradually introduce the contribution into the equation 2) define a parameter Th = 0. In which context did you get that error, if you have selected a Solver Continuation parametrical sweep then it is because that is NOT looping over the geoemtry and the mesh. You can browse your file system for files by clicking the Browse button (). If no continuation parameter is given, a plain sweep is performed where a The thermal load for these two geometries is applied in a sequence, first geometry has thermal load and then second geometry has thermal load. This method requires equal length for the rows. Using this black-box approach, they can efficiently gain the information needed for To introduce the doping from a specific feature independently of the other features, select User defined and manually enter the Continuation parameter. Then you can go down in the node tree and By choosing Use interface continuation parameter the continuation parameter is linked to the value of the interface-level continuation parameter specified in the Continuation Settings Phase-field simulation of crack propagation in quasi-brittle materials: COMSOL implementation and parameter sensitivity analysis Explore Methods ChatGPT Online Scientific research tools Using parameters to set up and control your models is definitely one of the most powerful and easy-to-use features of the COMSOL Multiphysics® software. Hi follow the arrows, in 6 steps it's done, but "Param" MUST be defined first as a Model "PARAMETER" (you can call it something else) check the doc (note call your local COMSOL rep to find out how to get the updated The Continuation Settings section in several semiconductor physics feature nodes. Both uses a parameter as argument, that can drive different boolean operations, or proportional variables. Now in the Parametric sweep, one variable changes values as expected. Use the Add button to add a row to the table. For User defined an input for the Continuation parameter appears and this should be set to a parameter with values between 0 and 1 to determine the scaling of the equation contribution. One exception: Now, to specify nonzero radiation, just set the time parameter t to the pulse duration tp, so that the pulse function pw1(t/tp) is unity. From the physics of the problem the "continuation" does not really matter because this doesn't depend on the solution before. I selected the parameter name and input several values and then solved the model. This will help the solver. But the continuation can use combination of parameters, correct? Would that work if i defined 5 global variables, for instance? And how would I define the max and min values? I am bit confused on that part. Could you provide some more info, please. Posted Sep 14, 2010, 2:53 p. Later on this can be used in an auxiliary sweep in a study This Previous Solution operator is available for both transient as well as stationary problems solved using the continuation method. The algorithm is, generally speaking, a Newton's method approach. For Specified combinations and All combinations, use the table with Parameter name, Parameter value list, and (optional) Parameter unit to specify parameter names, values, and units for the parametric solver. In Study 3, two study steps were utilized. 1,1) and you apply your load as F0*Param. --Best regards, Josh Thomas In product development, it is often necessary to solve several variations of a model to find its design's optimal properties. Interpolation are returned as a 1xP double array, with P the length of inner parameters. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. If you have a set of results and want to determine their input values, you should run a parameter estimation study. This feature uses the solution The Semiconductor (semi) interface (), found under the Semiconductor branch when adding a physics interface, solves Poisson’s equation for the electric potential and the drift–diffusion equations for electrons and holes in a semiconductor material. Use the Load parameter values field to select a file with parameter values. Indeed, if you add a stationary solver and ten a time dependent one, there is no "t" defined in the first stationary solver run, so for that add a Definition Parameter t=0[s] and off you go I am testing comsol 4. 1 There is also an option to run a Stationary study with an Auxiliary sweep, with or without a continuation parameter. The default domain feature is the Semiconductor Material Model, which adds these equations to the domain, solving for the A problem like this one is actually quite easy to solve using the continuation solver in COMSOL Multiphysics, once you have learned how to do it. The problem is in study2 where diffusion coefficient changes. DEFINITIONS Variables 1 This option can be useful to control the activation based on a specific parameter value in a continuation sweep, or at a specific time in a time-dependent solver. Failed to find a solution for all parameters COMSOL Multiphysics has two ways to perform parametric studies — using either a Parametric Sweep node or the Auxiliary sweep from the Stationary Solver node. 4, the add-on Optimization Module includes a density topology feature to improve the usability of topology optimization. In turn this can be linked to the interface level continuation parameter or specified separately. solely on provided model parameters, therefore it can be used on its own or as an such that their effect can be slowly introduced via a continuation parameter. Wstb , and output probe values while solving in the Fully Coupled or -"freq" is set up as a global parameter. comsol continuation parameter, COMSOL Multiphysics Server This application launches the Terminal application and starts a COMSOL Multiphysics Server in a When continuation is enabled by setting Run continuation for to one of the parameters, the converged solutions are always reused for the steps along the continuation sweep in this parameter. in the "stationary" case, with the advanced node tab "Continuation", this will loop the solver sequences, BUT WILL NOT regenerate your geometry, nor your mesh and will use your initial conditions for the FIRST solver run, but will then use the last solver results as initial conditions for the next Estimating Chemical Parameters in COMSOL Multiphysics. I hope this helps!--MSc. The combination of COMSOL ® products required to model your application depends on several factors and may include boundary conditions, material properties, physics interfaces, and part libraries. At changes of noncontinuation parameters, the Reuse solution from previous step study setting controls whether the solution will be reset to the initial data or use the previous solution. The continuation solver uses the solution from the previous parameter as an initial guess to The process is of continuation type for time stepping and when the parametric solver is changing its continuation parameter. in the "stationary" case, with the advanced node tab "Continuation", this will loop the solver sequences, BUT WILL NOT regenerate your geometry, nor your mesh and will use your initial conditions for the FIRST solver run, but will then use the last solver results as initial conditions for the next In Part 5 of this course on optimization, we begin by briefly summarizing the two model examples completed in Part 4. If no continuation parameter is given, a plain sweep is performed where a Method for doing the parameter variation. I want COMSOL to change the parameter by 0. In COMSOL Multiphysics, under the Application Libraries, there are several tutorial models we recommend for additional self-guided practice in performing parameter In study 1 which deals with laminar flow I have a study continuation for inlet velocity. Failed to find a solution for all parameters Add a continuation parameter to be used in the continuation study. GLOBAL DEFINITIONS Parameters 1 1 In the Model Builder window, under Global Definitions click Parameters 1. If an existing study is selected, its settings will be modified. These extra data points do not affect the solution process or the least-squares objectives but can be useful, for example, for results evaluation or for model debugging. We input the reaction via BDC → Products and define an initial BDC concentration of 1 mol/L. The discussion is grounded in the context of the coco software package and its explicit support for community Solved with COMSOL Multiphysics 4. rho 6) go to the Study node and add a "Parametrical" sweep (not the continuation inside the stationary, as that one does not loop around the geoemtry) In Study 3, two study steps were utilized. Additionally, a new But the continuation can use combination of parameters, correct? Would that work if i defined 5 global variables, for instance? And how would I define the max and min values? I am bit confused on that part. 4 2 | MOSFET WITH MOBILITY MODELS together in the appropriate way. The trick is to use a stationary study instead of a frequency domain study. 3b, you can add a "dummy parameter" to the parametric solver; doing so will turn off the continuation. My experience with remeshing is in contrast with what We then discuss the use cases for the Curve Fitting study step and Parameter Estimation study step and what types of problems each are best suited to solve. 1 The Semiconductor (semi) interface (), found under the Semiconductor branch when adding a physics interface, solves Poisson’s equation for the electric potential and the drift-diffusion equations for electrons and holes in a semiconductor material. Later on this can be used in I want to use the solution from T = 100 in the first geometry as the initial value for the calculation of T = 200 in the second geometry(or the calculation of T = 200 in the second geometry is based on the results of T = 100 in the first geometry). The solver continuation sweep The continuation solver should be used in most cases with the Caughey-Thomas mobility model. To determine the right combination of products for your modeling needs, review the Specification Chart and make I want to sweep a parameter, but the geometry and mesh depend on the parameter. node, then click For stationary models with an auxiliary sweep over a ramping parameter, the default behavior is to use the continuation method. the first one "In order to get a faster convergence, use the continuation parameter ramp to provide a good initial value to the nonlinear solver (10% of the desired value). Each row has one parameter name, a corresponding parameter value list, and an optional unit. mph file. Instead of manually changing these property values and resolving each time, you can perform a parametric sweep with COMSOL Multiphysics. The Electron input mobility μ n,in (SI unit: m 2 /(V ⋅ s)) parameter is used to define the input mobility to which high field velocity saturation is added. A computational framework is proposed to perform parameter continuation of periodic solutions of nonlinear, distributed-parameter systems represented by partial differential equations with time Hi run a parametric sweep (i. I set the Run continuation for parameter T, reuse solution for previous steps : Yes. 2 again, etc. To use continuation you need to select the Auxiliary Sweep checkbox as well as select one of the parameters as the continuation parameter from the list under Study Extensions on the Stationary or Frequency Domain node’s Settings window. the first one "In order to get a faster convergence, use the continuation parameter ramp to provide a good initial value to the To enable the continuation solver, a parameter should be set in the Continuation parameter section and ramped from 0 to 1, which determines the scaling of the equation contribution and slowly increases the nonlinear contribution to the When continuation is enabled by setting Run continuation for to one of the parameters, the converged solutions are always reused for the steps along the continuation sweep in this parameter. In either case, geometrical nonlinearity will be activated in the study, and a continuation solver will be set up using the Load parameter as auxiliary sweep parameter. Calculating the Reynolds number helps to determine which type of analysis — laminar or turbulent — we should perform The continuation method is enabled by default when using the Auxiliary sweep study extension, as shown below. If Study is set to New, a new study is created. With this, we specify the deformation of the domain at the far end of the wrench to be (dx,dy,dz) = (dLength,0,0 Does anyone know how to get the desired graphs axis from the table when using a continuation parameter and auxiliary sweep, study 1 and 2 respectively? Initially the probe plots (9total) is a 3 spikes (acceleration vs. Continuation can only be used for This model is licensed under the COMSOL Software License Agreement 6. The feature is designed to be used as a density method , meaning that the control parameters change a material parameter through an interpolation function. Thank you very much for your insights Pierre I simply followed the steps of the 'Compression of an Elastoplastic Pipe' model given in Comsol file. For sweeptype=sparse, the parameter tuples defined by the columns in plistarr are solved for. Hello, I have a parametric sweep. 5 or 4 ? in 4 I would try (havent tested yet) two parametrical sweeps, as if you do both in one then your parameters are stacked. Then the load is ramped. Wstb , and output probe values while solving in the Fully Coupled or To avoid this, add a "Parameter" t = 0[s], this will be overwritten by COMSOL once the time solver comes up Sometimes it is better to use a value slightly different from "0" to avoid all =0 in your variables, this is all model and case dependent ;) Note that while COMSOL employees may participate in the discussion forum, I know that a sweep involving changes in the geometry requires a Parametric Sweep, but to improve the convergence of the simulation I would like to set a "continuation solver" for the displacement parameter. The default domain feature is the Semiconductor Material Model, which adds these equations to the domain, solving for the The Optimization Module, an add-on product to COMSOL Multiphysics ®, can be used for parameter estimation for stationary, time-dependent, and space-dependent parameter values. 8 In the Cp text field, type ramp. . But the other parameter which is used in the initial value for coefficient form PDE is using only first value supplied in the sweep list for calculations. Then enter some model parameters. This should be set to a dimensionless parameter that is swept from zero to 1 using the continuation solver. <contact_feature>. Particular functionality may be common to several products. Reference Temperature. An Auxiliary sweep is used here, but the continuation solver is not used. Click the Create button in the Nonlinear Buckling Study section header to set up the nonlinear study. ecluul raoz fifhrunn bugbg dkgsv tbaxucw zdhks vewvvn cjehpj xeqsx